Health insurance is insurance that pays for medical expenses. It is sometimes used more broadly to include insurance covering disability or long-term nursing or custodial care needs. It may be provided through a government-sponsored social insurance program, or from private insurance companies. It may be purchased on a group basis (e.g., by a firm to cover its employees) or purchased by individual consumers. In each case, the covered groups or individuals pay premiums or taxes to help protect themselves from high or unexpected healthcare expenses. Similar benefits paying for medical expenses may also be provided through social welfare programs funded by the government.

By estimating the overall risk of healthcare expenses, a routine finance structure (such as a monthly premium or annual tax) can be developed, ensuring that money is available to pay for the healthcare benefits specified in the insurance agreement. The benefit is administered by a central organization such as a government agency, private business, or not-for-profit entity.

How it works

A health insurance policy is a contract between an insurance company and an individual or his sponsor (e.g. an employer). The contract can be renewable annually or monthly. The type and amount of health care costs that will be covered by the health insurance company are specified in advance, in the member contract or "Evidence of Coverage" booklet. The individual insurered person's obligations may take several forms:

Premium: The amount the policy-holder or his sponsor (e.g. an employer) pays to the health plan each month to purchase health coverage.

Deductible: The amount that the insured must pay out-of-pocket before the health insurer pays its share. For example, a policy-holder might have to pay a $500 deductible per year, before any of their health care is covered by the health insurer. It may take several doctor's visits or prescription refills before the insured person reaches the deductible and the insurance company starts to pay for care.

Copayment: The amount that the insured person must pay out of pocket before the health insurer pays for a particular visit or service. For example, an insured person might pay a $45 copayment for a doctor's visit, or to obtain a prescription. A copayment must be paid each time a particular service is obtained.

Coinsurance: Instead of, or in addition to, paying a fixed amount up front (a copayment), the co-insurance is a percentage of the total cost that insured person may also pay. For example, the member might have to pay 20% of the cost of a surgery over and above a co-payment, while the insurance company pays the other 80%. If there is an upper limit on coinsurance, the policy-holder could end up owing very little, or a great deal, depending on the actual costs of the services they obtain.

Exclusions: Not all services are covered. The insured person is generally expected to pay the full cost of non-covered services out of their own pocket.

Coverage limits: Some health insurance policies only pay for health care up to a certain dollar amount. The insured person may be expected to pay any charges in excess of the health plan's maximum payment for a specific service. In addition, some insurance company schemes have annual or lifetime coverage maximums. In these cases, the health plan will stop payment when they reach the benefit maximum, and the policy-holder must pay all remaining costs.

Out-of-pocket maximums: Similar to coverage limits, except that in this case, the insured person's payment obligation ends when they reach the out-of-pocket maximum, and the health company pays all further covered costs. Out-of-pocket maximums can be limited to a specific benefit category (such as prescription drugs) or can apply to all coverage provided during a specific benefit year.

Capitation: An amount paid by an insurer to a health care provider, for which the provider agrees to treat all members of the insurer.

In-Network Provider: (U.S. term) A health care provider on a list of providers preselected by the insurer. The insurer will offer discounted coinsurance or copayments, or additional benefits, to a plan member to see an in-network provider. Generally, providers in network are providers who have a contract with the insurer to accept rates further discounted from the "usual and customary" charges the insurer pays to out-of-network providers.

Prior Authorization: A certification or authorization that an insurer provides prior to medical service occurring. Obtaining an authorization means that the insurer is obligated to pay for the service, assume it matches what was authorized. Many smaller, routine services do not require authorization.

Explanation of Benefits: A document sent by an insurer to a patient explaining what was covered for a medical service, and how they arrived at the payment amount and patient responsibility amount.

Prescription drug plans are a form of insurance offered through some employer benefit plans in the U.S., where the patient pays a copayment and the prescription drug insurance part or all of the balance for drugs covered in the formulary of the plan.

Some, if not most, health care providers in the United States will agree to bill the insurance company if patients are willing to sign an agreement that they will be responsible for the amount that the insurance company doesn't pay. The insurance company pays out of network providers according to "reasonable and customary" charges, which may be less than the provider's usual fee. The provider may also have a separate contract with the insurer to accept what amounts to a discounted rate or capitation to the provider's standard charges. It generally costs the patient less to use an in-network provider.

Health plan vs. health insurance

Historically, HMOs tended to use the term "health plan", while commercial insurance companies used the term "health insurance". A health plan can also refer to a subscription-based medical care arrangement offered through HMOs, preferred provider organizations, or point of service plans. These plans are similar to pre-paid dental, pre-paid legal, and pre-paid vision plans. Pre-paid health plans typically pay for a fixed number of services (for instance, $300 in preventive care, a certain number of days of hospice care or care in a skilled nursing facility, a fixed number of home health visits, a fixed number of spinal manipulation charges, etc.) The services offered are usually at the discretion of a utilization review nurse who is often contracted through the managed care entity providing the subscription health plan. This determination may be made either prior to or after hospital admission (concurrent utilization review).

Comprehensive vs. scheduled

Comprehensive health insurance pays a percentage of the cost of hospital and physician charges after a deductible (usually applies to hospital charges) or a co-pay (usually applies to physician charges, but may apply to some hospital services) is met by the insured. These plans are generally expensive because of the high potential benefit payout — $1,000,000 to 5,000,000 is common — and because of the vast array of covered benefits.

Scheduled health insurance plans are not meant to replace a traditional comprehensive health insurance plans and are more of a basic policy providing access to day-to-day health care such as going to the doctor or getting a prescription drug. In recent years, these plans have taken the name mini-med plans or association plans. These plans may provide benefits for hospitalization and surgical, but these benefits will be limited. Scheduled plans are not meant to be effective for catastrophic events. These plans cost much less than comprehensive health insurance. They generally pay limited benefits amounts directly to the service provider, and payments are based upon the plan's "schedule of benefits". Annual benefits maximums for a typical scheduled health insurance plan may range from $1,000 to $25,000.